Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, data and so on. These systems may be multiple-access systems capable of supporting simultaneous communication of multiple mobile devices with one or more base stations.
A wireless communication device may include one or more transmitters and receivers to support bi-directional communication. A transmitter may condition and upconvert in-phase (I) and quadrature (Q) output baseband signals to obtain an output radio frequency (RF) signal that is more suitable for transmission via a wireless channel. The receiver may receive an input RF signal via the wireless channel and may downconvert the input RF signal to obtain in-phase (I) and quadrature (Q) input baseband signals.
The transmitter and receiver may each include separate branches for the in-phase (I) and quadrature (Q) signals. Ideally, the I branch and the Q branch have equal gain with a 90 phase difference from each other. However, imbalances may exist between the I branch and the Q branch. These imbalances may degrade the performance of the transmitter and the receiver. Benefits may be realized by improvements to I-Q imbalance calibration.